JS: create new common directory for all generated tests, migrate several tests there

js/js.translator/testData/box/inline/jsCodeVarDeclared.kt

@@ -0,0 +1,20 @@
+package foo
+
+// CHECK_CONTAINS_NO_CALLS: test
+
+internal inline fun sum(x: Int, y: Int): Int = js("var a = x; a + y")
+
+internal fun test(x: Int, y: Int): Int {
+    val xx = sum(x, x)
+    js("var a = 0;")
+    val yy = sum(y, y)
+
+    return sum(xx, yy)
+}
+
+fun box(): String {
+    assertEquals(4, test(1, 1))
+    assertEquals(8, test(1, 3))
+
+    return "OK"
+}